1. Field of the Invention
The invention relates to a novel elicitor protein for use in stimulating defense responses in plants.
2. Description of the Prior Art
Trichoderma virens (formerly known as Gliocladium virens) has been recognized as a mycoparasite and antibiotic-producing antagonist of plant pathogens, and has been used as an effective biocontrol agent of several soilborne root or seedling diseases [Aluko and Hering, 1970, Trans. Br. Mycol. Soc., 55:173-179; Beagle-Ristaino and Papavizas, 1985, Phytopathology, 75:560-564; Howell, 1982, Phytopathology, 72:496-498; Howell and Stipanovic, 1983, Can. J. Microbiol., 29:321-324; Weindling and Fawcett, 1936, Hilgardia, 10:1-16; and Wright, 1956, Plant Soil, 8:132-140]. T. virens produces gliotoxin and gliovirin, which are particularly effective antifungal antibiotics, as well as the antibacterial compound heptelidic acid and the antifungal compound viridin.
More recently, efforts have focused on techniques for improving the efficacy of T. virens as an antifungal biocontrol agent. These techniques have targeted reducing the production of the phytotoxic agent viridiol by T. virens, which may limit its use on valuable crops. Howell has described the addition of sterol inhibiting fungicides to the developing fungus cultures to reduce the production of viridiol (U.S. Pat. No. 5,268,173). Howell has also described the production of mutant strains of T. virens which are deficient for production of viridiol.